Obj. 3.17 Describe experiments to investigate the refraction of light, using rectangularblocks, semicircle blocks and triangular prisms

Obj. 3.16 Construct ray diagrams to illustrate the formation of a virtual image in a plane mirror

For plane mirrors the image is:

·         The same as the object

·         The same distance as the object from the mirror

·         Virtual (not real)

·         Upright

·         Laterally Inverted

Obj 3.15 Recall that the angle of Incidence equals the angle of reflection

*All light waves are transverse waves.

*A light ray is a narrow beam of light.

*Light always travels in straight lines.

*Like other waves, light can be diffracted, refracted and reflected.

Reflection

When measuring the angle of incidence the angle of

reflection will ALWAYS be equal, this is evident here in this diagram:

 angle of incidence  (i) = angle of reflection (r)

In a plane mirror the image is always reflected, example of a plane mirror would be dressing mirrors, security mirrors for checking under vehicles, dental mirrors for examining teeth, periscopes.

A convex mirror always gives a smaller version of the image, an example of a convex mirror would  be a car’s review mirror and a shop’s security mirror.

 

As a light wave approaches one’s eye it may either be vertically polarised (moving up and down – like an ocean wave) or horizontally polarised (moving side to side).  Light emitted from a lamp will contain both these properties however a reflection from the surface of glass or water may just have one type.

Opaque materials do NOT allow light to pass through whereas transparent materials DO let light pass through.